<?php
namespace Mageplaza\HelloWorld\Block;
class Products extends \Magento\Framework\View\Element\Template
{

    protected $_orderCollectionFactory;

    public function __construct(
        Magento\Framework\App\Action\Context $context,
        \Magento\Sales\Model\ResourceModel\Order\CollectionFactory $orderCollectionFactory
    )
    {
        $this->_orderCollectionFactory = $orderCollectionFactory;
        parent::__construct($context);

    }


    public function getOrderCollection()
    {
        $collection = $this->_orderCollectionFactory->create()
            ->addAttributeToSelect('*')
            ->addFieldToFilter($field, $condition); //Add condition if you wish

        return $collection;

    }
}